Biomedical subjects

Shoki Takahashi

Publications and source records attributed to Shoki Takahashi.

At least 55 records · Page 3Linked to original sources

PubMed2004

[Peripheral venous stenoses of hemodialysis shunts: improved long-term patency rates with stent placement].

PURPOSE: The purpose of this study was to evaluate the effectiveness of endovascular stents placed in the peripheral veins of hemodialysis shunts. MATERIALS AND METHODS: 156 endovascular stents were placed in the peripheral veins of 155 hemodialysis shunts with 220 stenoses. Among these, 106 stenoses of 93 hemodialysis shunts had been treated by percutaneous transluminal angioplasty (PTA) before stent placement. RESULTS: The initial success rate was 97.7%. Primary radiologic patency rates of the stents at 6 months, 1 year, and 2 years were 69.8%, 49.1%, and 45.8%, respectively. Secondary radiologic patency rates at 1 year, 2 years, and 3 years were 94.0%, 91.8%, and 88.0%, respectively. Primary clinical patency rates at 6 months, 1 year, and 2 years were 64.4%, 43.4%, and 27.3%; while secondary clinical patency rates at 1 year, 2 years, and 3 years were 93.5%, 86.5%, and 73.4%, respectively. Radiologic and clinical primary patency rates of 106 stenoses and 93 hemodialysis shunts were significantly higher than those of PTA that had been performed before stents were placed. CONCLUSION: Stent placement for stenoses of the peripheral veins of hemodialysis shunts recurring in three months and treated by PTA alone can improve long-term patency.

Adult↗

PubMed2003

Characteristics of Rathke's cleft cyst in MR imaging.

PURPOSE: Symptoms, macroscopic appearances and microscopic findings of Rathke's cleft cysts with magnetic resonance (MR) imaging. PATIENTS AND METHODS: We analyzed the data from 31 patients with pathologically confirmed Rathke's cleft cysts. MR appearances were evaluated on T1WI, T2WI and contrast T1WI. Symptoms, macroscopic appearances and pathological findings were obtained from available medical records. We analyzed the images according to the following criteria: 1. findings on the location and shape of the lesions and form of the lesional wall; 2. the relationship between the maximum diameter of the lesions and symptoms; 3. the relationship between MR and macroscopic appearance; 4. the sites of adjacent contrast enhancement. RESULTS: The lesions were located mostly in both the intrasellar and suprasellar regions for a total of 87%. All lesions revealed either an oval or dumbbell shape with a smooth lesional wall. When correlated with physical symptoms, asymptomatic cases were associated with smaller lesions, while visual disturbances and dizziness were associated with relatively larger lesions. MR lesion signal intensity was related to the content of macroscopic appearance to some degree: the selected lesions showed shortening of T1 and T2 relaxation times in relation to the increase in protein concentration. This should have been macroscopically reflected in the color and turbidity of the liquid within the cyst. Adjacent contrast enhancement around the lesion was found at various sites, but anterior enhancement was most frequent. Circumferential enhancement was revealed to be derived from inflammatory changes. CONCLUSION: Rathke's cleft cyst exhibits a varied MR signal. It may be difficult to differentiate from craniopharyngioma from the intensity alone.

Adolescent↗

PubMed2003

Steroid sulfatase and estrogen sulfotransferase in the atherosclerotic human aorta.

Various epidemiological studies have demonstrated a relatively low incidence of cardiovascular events in premenopausal women and its marked increment after menopause. In addition, estrogens have been postulated to exert direct anti-atherogenic effects via binding to estrogen receptors in vascular smooth muscle cells (VSMCs). However, not all postmenopausal women develop atherosclerosis despite decreased levels of serum estrogen. Therefore, we believe it is important to examine the status of estrogen metabolism in situ in the human cardiovascular system. Estrone sulfate (E1S) is a major circulating plasma estrogen that is converted into the biologically active estrogen, estrone (E1) by steroid sulfatase (STS). E1 is also sulfated and reverted into E1S by estrogen sulfotransferase (EST). These two enzymes have recently been shown to play important roles in the in situ estrogen actions of estrogen-dependent human tissues and various sex steroid-dependent tumors. STS and EST, however, have not been studied in detail in the human vascular system associated with atherosclerotic changes. In the present study, we evaluated the relative abundance of STS- and EST-immunoreactive protein and mRNA expression in human aorta using immunohistochemistry and reverse transcription followed by quantitative polymerase chain reaction in addition to enzyme activity. STS expression levels were found to be significantly higher in the VSMCs obtained from female aortas with mild atherosclerotic changes than in those with severe atherosclerotic changes and in male aortas regardless of atherosclerotic changes. EST expression levels in the VSMCs of these aortas, however, were significantly higher in female aortas with severe atherosclerotic changes and in male aortas than in female aortas with mild atherosclerotic changes. We believe it is important to examine factors regulating the expression and activity of these estrogen-metabolizing enzymes in the human aorta. Various cytokines have been proposed to function as regulators of these enzymes in other tissues. In the present study, we studied the effects of interleukin (IL)-1beta, known to be produced in human atherosclerotic lesions, on the expression of these enzymes using cultured human VSMCs originally obtained from a female patient. IL-1beta markedly inhibited the expression of STS mRNA and enzyme activity, but stimulated the expression of EST mRNA and enzyme activity. In addition, IL-1beta also reduced E2 production from E1S and E1 in VSMCs. Results from the present study seem to suggest that the expression levels of both STS and EST mRNA and activity may be significantly associated with the degree of atherosclerotic changes in the female aorta, which may be related to cytokines produced in situ, such as IL-1beta, in human atherosclerotic lesions.

Adult↗

PubMed2003

Adrenal adenomas: relationship between histologic lipid-rich cells and CT attenuation number.

OBJECTIVE: To evaluate the relationship between lipid-rich cells of the adrenal adenoma and precontrast computed tomographic (CT) attenuation numbers in three clinical groups. MATERIALS AND METHODS: Thirty-five surgically resected adrenal adenomas were used. The clinical diagnoses of the patients included 13 cases of primary aldosteronism, 15 cases of Cushing's syndrome, and 7 non-functioning tumors. The number of lipid-rich clear cells was counted using a microscopic eyepiece grid that contained 100 squares. The results were expressed as the percentages of lipid-rich areas. RESULTS: There was a strong inverse linear relationship between the percentage of lipid-rich cells and the precontrast CT attenuation number (R(2)=0.724, P<0.0001). There were significantly more lipid-rich cells in the primary aldosteronism and non-functioning tumor cases compared to cases of Cushing's syndrome (P=0.007 and 0.015, respectively). The CT attenuation numbers of the primary aldosteronism cases were significantly lower than those of Cushing's syndrome (P=0.0052). Furthermore, the CT attenuation numbers of the non-functioning tumor cases were lower than those of Cushing's syndrome cases. CONCLUSION: We showed that adrenal adenomas in primary aldosteronism and non-functioning tumors contain significantly more lipid-rich cells than those in Cushing's syndrome. They also showed significantly lower attenuation than that in Cushing's syndrome on CT scans. Our results suggest that precontrast CT attenuation numbers may be helpful in the differentiation of adenomas from non-adenomatous lesions, which include malignancies.

Adenoma↗

PubMed2003

Changes in brain activation patterns associated with learning of Korean words by Japanese: an fMRI study.

We used functional magnetic resonance imaging (fMRI) to explore the change in brain activation associated with the learning of Korean words written in Han-gul characters (K-words) by young Japanese at two stages. Subjects were 12 right-handed native Japanese without previous knowledge of Korean words and characters. On the first day they were taught the pronunciation and meaning of 20 K-words. Then, after the first fMRI session (on day 2), they were given a set of 20 cards with the words and corresponding photographs. They also received a tape and were instructed to memorize the 20 K-words by studying them every day until the day of the second fMRI session (day 16). During the fMRI sessions, 20 Japanese words written in kana syllabograms (J-words) and the 20 previously presented K-words, as well as 20 new K-words (Kn-words) were presented visually for silent reading. The first J-word reading, relative to the first K-word reading, showed activation in the left angular gyrus. K-word reading relative to J-word reading during both sessions showed activation in occipital regions. Within these activated areas, session by condition interaction was found only in the left angular gyrus. The interaction between session and condition resulted from the fact that the differences in blood oxygenation-level-dependent signals between K-words and J-words and between Kn-words and J-words were significantly greater in the first session than in the second session. From the results, we concluded that patterns of brain activation changed as the memory of the 20 K-words became fixed through daily practice and that reading of both Korean words and Japanese syllabograms engaged the left angular gyrus.

Adult↗

PubMed2003

Metabolic properties of band heterotopia differ from those of other cortical dysplasias: a proton magnetic resonance spectroscopy study.

PURPOSE: To assess the biochemical properties of band heterotopia in comparison with other cortical developmental malformations (CDMs) by using proton magnetic resonance spectroscopy (1H-MRS). METHODS: We performed localized single-voxel 1H-MRS studies on 13 patients [five band heterotopia (BH), two focal cortical dysplasia (CD), two unilateral CD, one bilateral perisylvian dysplasia, three hemimegalencephaly]. CDMs other than BH were categorized as CD. Spectra were acquired from volumes of interest (VOIs) localized in the CD and in normal-appearing cortex on the contralateral side. In BH patients, the VOIs were the external cortex and the laminar heterotopia. For the BH study, spectra also were obtained from the cortex of age-matched normal volunteers. RESULTS: The spectra of CD lesions were characterized by significantly lower ratios of N-acetyl aspartate to creatine (NAA/Cr) and by higher choline to Cr (Cho/Cr) ratios than in the contralateral remote cortex (p = 0.01 and 0.01, respectively). The NAA/Cr and Cho/Cr ratios of the external cortex of BH were not significantly different from those of normal volunteers. The NAA/Cr ratio of the laminar heterotopia was not significantly different from that of the external cortex (p = 0.12) or normal volunteers (p = 0.60), whereas Cho/Cr was significantly higher in laminar heterotopias than in the external cortex (p = 0.04) or controls (p = 0.03). CONCLUSIONS: 1H-MRS can distinguish between the metabolic properties of BH and CD.

Adolescent↗

PubMed2003

Time-related changes of radiofrequency ablation lesion in the normal rabbit liver: findings of magnetic resonance imaging and histopathology.

RATIONALE AND OBJECTIVES: To study time-related magnetic resonance imaging (MRI) and histopathological findings after radiofrequency ablation (RFA) in the normal liver. METHODS: Under ultrasound guidance, RFA was performed in 22 rabbits with a 15-gauge expandable probe inserted into the liver. The RF power was applied at 10 W initially with a 5-W increment every minute until RF power "roll-off" occurred. The rabbits subjected to postmortem MRI at 3 days (n = 6), 2 weeks (n = 6), 4 weeks (n = 6), and 12 weeks (n = 4) after RFA. Spin-echo (SE) T(1)-weighted image (WI) (TR/TE=500/12) and fast SE T2-WI (TR/TE= 3500/99) were obtained. The liver specimens were excised and processed for conventional histologic study. The MRI and pathologic findings were compared qualitatively and quantitatively. RESULTS: The lesion diameters measured with MRI and liver specimen were well correlated (P < 0.05). The coagulated regions presented 2 of 4 laminar patterns on T1/T2-WI 3 days after RFA, and 2 of 3 laminar patterns on T1/T2-WI 2 to 4 weeks after RFA. 12 weeks after RFA, the signal intensity in coagulated regions increased on T1-WI with a 2-laminar pattern still visible on T2-WI, the same as that of 2 to 4 weeks. The observed pathologic changes (enlarged sinusoids, marginal fibrous tissue and hepatocyte degeneration) could be responsible for the MRI laminar patterns and signal intensity changes. CONCLUSION: The time-related pathologic changes of RFA lesions in rabbit livers can be reflected as laminar patterns on MR images. Understanding of the zone structure of the lesions is useful for the evaluation of follow-up MRI.

Animals↗

PubMed2003

Acute superior mesenteric artery embolism: rapid reperfusion with hydrodynamic thrombectomy and pharmacological thrombolysis.

PURPOSE: To report a case of acute superior mesenteric artery (SMA) embolism successfully treated with hydrodynamic thrombectomy and pharmacological thrombolysis. CASE REPORT: A 67-year-old man was admitted to the hospital with acute severe abdominal pain. Selective angiography via a femoral puncture revealed a complete embolic occlusion distal to the first jejunal branch of the SMA. Hydrodynamic thrombectomy resolved the severe abdominal pain of the patient in approximately 10 minutes after the start of thrombectomy. Local continuous thrombolysis with urokinase resulted in near complete restoration of the mesenteric flow after 24 hours. The patient made an uneventful recovery and continues to do well on warfarin therapy 8 months after treatment; he has shown no evidence of malabsorption. CONCLUSIONS: Although insertion of the device into the SMA via a femoral puncture is a difficult approach, we propose that hydrodynamic thrombectomy followed by local thrombolysis is a useful treatment for acute superior mesenteric artery embolism.

Acute Disease↗

PubMed2003

Practical visualization of internal structure of white matter for image interpretation: staining a spin-echo T2-weighted image with three echo-planar diffusion-weighted images.

BACKGROUND AND PURPOSE: To our knowledge, no method satisfactory for clinical use has been developed to visualize white matter fiber tracts with diffusion-weighted MR imaging. The purpose of this study was to determine whether superposition of a spin-echo T2-weighted image and a color-coded image derived from three orthogonal diffusion-weighted images could show fiber tract architecture of the brain with an image quality appropriate for accurate reading with a computer monitor. METHODS: MR images from 50 consecutive cases were reviewed. Three diffusion-weighted images per section were acquired with three orthogonal motion-probing gradients. These images were registered to a corresponding spin-echo T2-weighted image. A color-coded image was synthesized from three diffusion-weighted images by assigning red, green, or blue to each diffusion-weighted image and then adding a spin-echo T2-weighted image with a weighting factor. The ability of the superposed image to delineate the white matter pathways was evaluated on the basis of the known anatomy of these pathways and qualitatively compared with that of the spin-echo T2-weighted image. RESULTS: The main white matter fiber pathways, in particular the superior longitudinal fascicle, corpus callosum, tapetum, optic radiation, and internal capsule, were more clearly and easily identified on the superposed image than on the spin-echo T2-weighted image. The time required to produce the superposed image was approximately 40 minutes. CONCLUSION: Superposition of a spin-echo T2-weighted image and a color-coded image created from three orthogonal diffusion-weighted images showed structures of the brain that were not clearly visible on the spin-echo T2-weighted image alone. Such superposition presents images that are easy to interpret correctly.

Adolescent↗

PubMed2002

Neural basis of the retrieval of people's names: evidence from brain-damaged patients and fMRI.

The aim of this study was to identify the neuroanatomical basis of the retrieval of people's names. Lesion data showed that patients with language-dominant temporal lobectomy had impairments in their ability to retrieve familiar and newly learned people's names, whereas patients with language-nondominant temporal lobectomy had difficulty retrieving newly learned people's names. Functional magnetic resonance imaging experiments revealed activations in the left temporal polar region during the retrieval of familiar and newly learned people's names, and in the right superior temporal and bilateral prefrontal cortices during the retrieval of newly learned information from face cues. These data provide new evidence that the left anterior temporal region is crucial for the retrieval of people's names irrespective of their familiarity and that the right superior temporal and bilateral prefrontal areas are crucial for the process of associating newly learned people's faces and names.

Adolescent↗

PubMed2002

Neural basis of temporal context memory: a functional MRI study.

Temporal context information is crucial to understanding human episodic memory. Human lesion and neuroimaging data indicate that prefrontal regions are important for retrieving temporal context memory, although the exact nature of their involvement is still unclear. We employed functional magnetic resonance imaging (fMRI) to elucidate the neural basis of two kinds of temporal context memory: the temporal order of items between lists and within a list. On the day of the fMRI experiment, subjects memorized a list of 30 pictures in the morning and another list of 30 pictures in the afternoon. During the scanning session, the subjects performed three tasks. In a between-lists task, they were asked to judge the temporal order between two items that had been presented in different lists. In a within-list task, they were asked to judge the temporal order between two items that had been presented in a single list. We found bilateral prefrontal activities during these two temporal context memory tasks compared with a simple item-recognition task. Furthermore, in direct comparison between these two tasks, we found differential prefrontal activities. Thus, right prefrontal activity was associated with temporal order judgment of items between lists, whereas left prefrontal activity was related to temporal order judgment of items within a list. These results indicate that retrieval processes of two kinds of temporal context memory are supported by different, but overlapping, sets of cerebral regions. We speculate that this reflects different cognitive processes for retrieving temporal context memory between separate episodes and within a single episode.

Adult↗

PubMed2002

Abnormal white matter lesions with sensorineural hearing loss caused by congenital cytomegalovirus infection: retrospective diagnosis by PCR using Guthrie cards.

We report on two patients with congenital cytomegalovirus (CMV) infection asymptomatic at birth that was diagnosed retrospectively by polymerase chain reaction (PCR) of CMV DNA using blood stored on Guthrie cards. Neuroimaging studies showed abnormal myelination without any gray matter abnormalities. In the differential diagnosis of patients with abnormal white matter lesions and sensorineural hearing loss, one should consider congenital CMV infection. When investigating the etiology of patients with behavioral problems, migrational disorder, or white matter disease, PCR analysis of CMV DNA using blood stored on Guthrie cards might be helpful.

Blood Specimen Collection↗

PubMed2002

Demonstration of the artery of Adamkiewicz at multi- detector row helical CT.

PURPOSE: To assess the ability of multi-detector row helical computed tomography (CT) to depict the artery of Adamkiewicz. MATERIALS AND METHODS: Seventy patients with vascular diseases underwent multi-detector row helical CT of the entire aorta and iliac arteries. The artery of Adamkiewicz was examined on multiplanar and curved planar reformation images and on cine-mode displays. The visualization of the artery of Adamkiewicz, as well as its branching level and side of origin, was investigated. RESULTS: In 63 (90%) of the 70 patients, at least a single artery of Adamkiewicz was clearly visualized from the intervertebral foramen to the hairpin-shaped union with the anterior spinal artery. Two arteries of Adamkiewicz were identified in 15 (24%) of 63 patients. Fifty-five arteries of Adamkiewicz (71%) originated from the left side. Seventy-two (92%) originated between T8 and L1. Neither the intercostal vein nor the posterior spinal vein were visualized in 57 of 63 patients. Continuity of the entire length, starting from the stem of the intercostal or lumbar artery and proceeding to the artery of Adamkiewicz and finally to the anterior spinal artery, was traceable on cine-mode displays or on curved planar reformation images in 20 of 63 patients. CONCLUSION: Multi-detector row helical CT depicts the artery of Adamkiewicz in a high percentage of patients.

Adult↗

PubMed2002

Predominant involvement of ipsilateral anterior and posterior circulations in moyamoya disease.

BACKGROUND AND PURPOSE: We encountered several patients with childhood onset of moyamoya disease in whom the ipsilateral anterior and posterior circulations were predominantly involved. This study investigated whether this is an angiographic characteristic of this disease. METHODS: We evaluated steno-occlusive lesions on angiograms of 85 patients with pediatric onset of moyamoya disease, using two 4-stage angiographic classification scales for the internal carotid artery and posterior cerebral artery systems (ICA and PCA staging, respectively) and determined whether lesions with more advanced ICA and PCA stages were on ipsilateral sides. RESULTS: When positive laterality was defined as the presence of a difference by > or =1 stage between the stages on both sides, lateralities in the ICA stages and in the PCA stages were present in 40 (47%) and 27 patients (32%), respectively. Lesions with more advanced ICA and PCA stages were on the same side, with significant probability (P=0.024, Fisher's exact test). Lateralities in both ICA and PCA lesions were found in 17 patients. In 14 (82%) of the 17 patients, the more advanced side of ICA lesions was the same as that of PCA lesions, while it was contralateral in 3 patients (18%). CONCLUSIONS: In pediatric-onset moyamoya disease, asymmetrical involvement of bilateral ICAs and PCAs was common, and the ipsilateral ICA and PCA tended to be predominantly involved.

Adolescent↗

PubMed2002

Imaging of ischemic but viable myocardium using a new 18F-labeled 2-nitroimidazole analog, 18F-FRP170.

UNLABELLED: RP170, 1-(2-hydroxy-1-[hydroxymethyl]ethoxy)methyl-2-nitroimidazole, is a new hypoxic radiosensitizer. We recently succeeded in labeling this compound with 18F to make 18F-FRP170, 1-(2-fluoro-1-[hydroxymethyl]ethoxy)methyl-2-nitroimidazole. In this study, we attempted to visualize the ischemic but viable myocardium of rats as hot-spot images using 18F-FRP170. We also compared the distribution of 18F-FRP170 with myocardial perfusion, fatty acid metabolism, and glucose metabolism. METHODS: In open-chest rats, the left coronary artery was ligated to make an ischemic myocardial model. We evaluated the myocardial accumulation of radiotracers by the double-tracer autoradiography technique. 14C-Iodoantipyrine (IAP), 125I-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP), and 14C-deoxyglucose (DG) were used as markers of myocardial perfusion, fatty acid metabolism, and glucose metabolism, respectively. Approximately 80 small circular regions of interest were placed throughout the left ventricular wall of the midventricular level section. The uptake in each region of interest was expressed as the percentage uptake of the average count in the remote area. We then defined the 18F-FRP170 high-uptake area (H-FRP) as that area where the percentage of FRP was >120% and the 18F-FRP170 low-uptake area (L-FRP) as that area where the percentage of FRP was <80%. RESULTS: On the 18F-FRP170 image of the ischemic myocardium, there was a low-uptake area in the center, which was bounded by a high-uptake area. The percentages of IAP in the H-FRP and the L-FRP were 48.5% +/- 5.8% and 2.2% +/- 0.2%, respectively; the percentages of BMIPP in the H-FRP and the L-FRP were 46.8% +/- 3.1% and 4.3% +/- 0.4%, respectively; and the percentages of DG in the H-FRP and the L-FRP were 107.0% +/- 6.8% and 4.3% +/- 0.4%, respectively. In diabetic rats, the percentages of DG in the H-FRP and the L-FRP were 407.7% +/- 14.9% and 72.5% +/- 5.0%, respectively, but the remote area on the DG image was insufficiently visualized. Histologic data using 2,3,5-triphenyltetrazolium chloride staining suggest that the high-uptake areas on 18F-FRP170 images reflect ischemic but viable myocardium. CONCLUSION: We succeeded in visualizing the ischemic but viable myocardium as a hot spot on the 18F-FRP170 image. 18F-FRP170 can be expected to provide important information for determining the necessity of coronary intervention in ischemic heart disease patients, including diabetic patients.

Animals↗

PubMed2002

[Performance evaluation of dual-head coincidence gamma camera for positron imaging].

AIM AND METHODS: We assessed the performance evaluation of a dual-head coincidence gamma camera (Millennium VG, General Electric, Milwaukee, USA) as a positron emission tomography (PET) scanner based on the measurement indicator for performance evaluation of PET device. RESULTS: The axial spatial resolution was 4.98 mm FWHM at the center of the field of view. The true high count-rate characteristic curve was relatively straight within the range 0-0.2 microCi/ml. The relative recovery coefficient was 0.1 with a diameter of 10 mm and 0.39 with a diameter of 20 mm. CONCLUSION: In this study, we had to make a some change in the protocols described in the measurement indicator for performance evaluation of PET devices.

Gamma Cameras↗

PubMed2002

Conspicuity and evolution of lesions in Creutzfeldt-Jakob disease at diffusion-weighted imaging.

BACKGROUND AND PURPOSE: Diffusion-weighted imaging can disclose distinct hyperintense lesions in Creutzfeldt-Jakob disease (CJD). However, these findings and chronologic changes of CJD at diffusion-weighted imaging have not been fully investigated. Our purpose was to assess the diagnostic value of diffusion-weighted imaging in depicting CJD-related lesions and in tracking the evolution of these lesions. We also compared the sensitivity of diffusion-weighted imaging in depicting CJD-related lesions to that of fluid-attenuated inversion recovery (FLAIR) imaging. METHODS: We reviewed findings in 13 patients with a diagnosis of CJD who underwent MR imaging, including diffusion-weighted imaging. Nine patients were initially examined within 4 months of onset of symptoms (early stage), and eight were examined 4 months or later (late stage). We evaluated four items: 1) distribution of lesions at diffusion-weighted imaging, 2) conspicuity of lesions at diffusion-weighted imaging and FLAIR imaging, 3) chronologic changes in lesions at diffusion-weighted imaging, and 4) chronologic changes in lesions revealed by apparent diffusion coefficient (ADC) maps. RESULTS: Patients had striatal lesions or cerebral cortical lesions or both. The thalamus was involved in only one patient, and the globus pallidus was spared in all patients. The sensitivity of diffusion-weighted imaging in depicting lesions was superior or at least equal to that of FLAIR imaging. Hyperintense lesions at diffusion-weighted imaging changed in extent and intensity over time. Unlike infarction, lesional ADC decreased for 2 weeks or longer. CONCLUSION: The progressively hyperintense changes in the striata and cerebral cortices at diffusion-weighted imaging are considered characteristic of CJD. Diffusion-weighted imaging may be useful for the early diagnosis of CJD.

Aged↗

PubMedDate not supplied

Optimization of tube potential-filter combinations for film-screen mammography: a contrast detail phantom study.

This study evaluated how tube potential-filter combinations [with a molybdenum (Mo) anode and either an Mo or a rhodium (Rh) filter] influence image quality and radiation dose to breasts of different thicknesses in film-screen mammography using a new mammography phantom (CDMAM Phantom Type 3.4). A 28-kVp/Mo tube potential-filter combination is recommended for a breast (phantom) thickness of 40 mm or less, 28 kVp/Rh for a breast (phantom) thickness of 60 mm or less, and 30 kVp/Rh for a breast (phantom) thickness greater than 60 mm.

Mammography↗